1. Field of the Invention
The present invention relates to a handling apparatus of a lead-frame used in resin sealed electronic components. More specifically, it relates to an apparatus which separates and takes out the lead-frame one by one from a plurality of lead-frames stacked in alignment.
2. Description of the Prior Art
In resin sealed or packaged type components such as capacitors, semiconductor devices or the like, resin molding using a rectangular sheet-type metal lead-frame is employed. For example, in a production process and pellet mounting process of the semiconductor device, a sheet of lead-frame is separated one by one from a column of lead-frames supplied in a stacked state and conveyed to the next process. As means for separating the lead-frame one by one, a vacuum suction or magnetic suction has been known. In such conventional separating means, the top lead-frame is sucked and separated with a vacuum suction pad or a magnet chuck from above the stacked lead-frame and conveyed to the pellet mounting position. The column of stacked lead-frames is placed on an elevating mechanism and lifted at the end of every separation aforementioned so that the top layer of lead-frame takes a prescribed position. Then, after the last lead-frame has been taken out, the elevating mechanism is descended to the initial position to repeat the above separating operation after supplying the new stacked lead-frames.
The lead-frame is formed by etching or pressing a metal sheet material. Accordingly, when a number of lead-frames processed by etching are stacked, a total weight is increased and it sticks together so closely that its separation is sometimes difficult. Also, when the lead-frame is processed by pressing, burrs produced at pressing were caught by the adjacent lead-frame. Therefore, by means of vacuum suction pad or magnet chuck, it is difficult to separate only one sheet from the stocked lead-frame, frequently resulted in such an accident as taking out a few lead-frames sticking to each other. Besides, in this case, it was also dangerous that an excessive lead-frame will drop while being transferred to the following process.
Also, in the separating means utilizing the vacuum suction pad or magnet chuck, since the top layer of lead-frame must be picked up from above the stocked lead-frame, the elevating mechanism or the like for arranging the top layer always at the prescribed position is required, thus complication and enlargement of the apparatus itself is unavoidable. In addition, the new lead-frame cannot be supplied during the separating operation, but only after the whole lead-frames are taken out and the elevating mechanism is descended and returned to the initial position, resulted in a considerable deterioration of the operability. Furthermore, the lead-frame has various sizes giving different locations to be sucked by the vacuum suction pad or magnet chuck depending on kinds, so that the sucking position must be changed accordingly, thus a flexible adaptability to various lead-frames was difficult.